Head FiberGel Spin features an extra textured surface for added spin and maximum control. FiberGEL Spin is designed with a solid Polyamide single fiber core and a wrap of 8 copolymer GEL Fibers. Composition: Polyamide single fiber center core 8 copolymer gel-fibers over a polyamide 6 inner wrap. Gauge: 16 g. Length: 40 ft.